Key molecule discovered in Venus's atmosphereMay 16, 2008Venus Express has detected the molecule hydroxyl on another planet for the first time. This detection gives scientists an important new tool to unlock the workings of Venus's dense atmosphere. Hydroxyl, an important but difficult-to-detect molecule, is made up of a hydrogen and oxygen atom each. It has been found in the upper reaches of the Venusian atmosphere, some 100 km above the surface, by Venus Express's Visible and Infrared Thermal Imaging Spectrometer, VIRTIS. The elusive molecule was detected by turning the spacecraft away from the planet and looking along the faintly visible layer of atmosphere surrounding the planet's disc. The instrument detected the hydroxyl molecules by measuring the amount of infrared light that they give off. The band of atmosphere in which the glowing hydroxyl molecules are located is very narrow; it is only about 10 km wide. By looking at the limb of the planet, Venus Express looked along this faint atmospheric layer, increasing the signal strength by about 50.
Hydroxyl is thought to be important for any planet's atmosphere because it is highly reactive. On Earth it has a key role in purging pollutants from the atmosphere and is thought to help stabilise the carbon dioxide in the martian atmosphere, preventing it from converting to carbon monoxide. On Mars it is also thought to play a vital role in sterilising the soil, making the top layers hostile to microbial life. The reactive molecule has been seen around comets, but the method of production there is thought to be completely different from the way it forms in planetary atmospheres. "Because the venusian atmosphere had not been studied extensively before Venus Express arrived on the scene, we have not been able to confirm much of what our models tell us by observing what is actually happening. This detection will help us refine our models and learn much more," says one of the Principal Investigators of the VIRTIS experiment, Giuseppe Piccioni, from the Istituto di Astrofisica Spaziale e Fisica Cosmica in Rome, Italy. On Earth, the glow of hydroxyl in the atmosphere has been shown to be closely linked to the abundance of ozone. From this study, the same is thought to be true at Venus. Now, scientists can set about estimating the amount of ozone in the planet's atmosphere. Venus Express has shown that the amount of hydroxyl at Venus is highly variable. It can change by 50% from one orbit to the next and this may be caused by differing amounts of ozone in the atmosphere. "Ozone is an important molecule for any atmosphere, because it is a strong absorber of ultraviolet radiation from the Sun," says Piccioni. The amount of the radiation absorbed is a key parameter driving the heating and dynamics of a planet's atmosphere. On Earth, it heats the stratosphere (layer of the atmosphere) making it stable and protecting the biosphere from harmful ultraviolet rays. Computer models will now be able to tell how this jump and drop in ozone levels over short intervals affects the restless atmosphere of that world. "Venus Express has already shown us that Venus is much more Earth-like than once thought. The detection of hydroxyl brings it a step closer," says Piccioni. He and his colleagues are only reporting the initial detection from a few orbits in their latest paper. They are working on the analysis of data from about 50 other orbits and more observations will follow. European Space Agency Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Mass Spectrometry Quantum cryptography Primary Care Angiography Tomato Alcohol Addiction Enzyme Mastectomy Aggression Invisibility Cloak Mortality Rate Kidney Cancer Aging Pulmonary Hypertension Smart-1 Cocoa Type 1 Diabetes Peptides Silver Volcanic Eruptions Bats Cancer Development Dead Zone Aneurysm Nanotechnology
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Related Venus Current Events and Venus News Articles Magnetic Tornadoes Could Liberate Mercury's Tenuous Atmosphere As the closest planet to the sun, Mercury is scorching hot, with daytime temperatures of more than 800 degrees Fahrenheit (approximately 450 degrees Celsius). When texting, eligible women express themselves better The book Men Are from Mars, Women Are from Venus and its gender stereotypes on how the sexes communicate remains fodder for debate, but two Indiana University researchers have confirmed one thing: When men and women talk through technology, it's the women who are more expressive. Caltech scientists lead deep-sea discovery voyage Scientists from the California Institute of Technology (Caltech) and an international team of collaborators have returned from a month-long deep-sea voyage to a marine reserve near Tasmania, Australia, that not only netted coral-reef samples likely to provide insight into the impact of climate change on the world's oceans, but also brought to light at least three never-before-seen species of sea life. Looking through Galileo's eyes In 1609, exactly four centuries ago, Galileo revolutionised humankind's understanding of our position in the Universe when he used a telescope for the first time to study the heavens, which saw him sketching radical new views of the moon and discovering the satellites orbiting Jupiter. Where did Venus's water go? Venus Express has made the first detection of an atmospheric loss process on Venus's day-side. Last year, the spacecraft revealed that most of the lost atmosphere escapes from the night-side. Venus comes to life at wavelengths invisible to human eyes A pale yellow-green dot to the human eye, Earth's twin planet comes to life in the ultraviolet and the infrared. New images taken by instruments on board ESA's Venus Express provide insight into the turbulent atmosphere of our neighbouring planet. Worlds in collision Two terrestrial planets orbiting a mature sun-like star some 300 light-years from Earth recently suffered a violent collision, astronomers at UCLA, Tennessee State University and the California Institute of Technology will report in a December issue of the Astrophysical Journal, the premier journal of astronomy and astrophysics. Volcanic Activity Shaped Mercury After All Scientists have long anguished over how little is known about Mercury, the innermost of the four terrestrial planetary bodies in our solar system. Active submarine volcanoes found near Fiji Several huge active submarine volcanoes, spreading ridges and rift zones have been discovered northeast of Fiji by a team of Australian and American scientists aboard the Marine National Facility Research Vessel, Southern Surveyor. Astonomers find tiny planet orbiting tiny star An international team of astronomers led by David Bennett of the University of Notre Dame has discovered an extra-solar planet of about three Earth masses orbiting a star with a mass so low that its core may not be large enough to maintain nuclear reactions. The result was presented Monday (June 2) at the American Astronomical Society annual meeting in St. Louis. More Venus Current Events and Venus News Articles |
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